Solvent-Probe NMR Imaging of Low-Density Polyethylene Rods: A Layered Structure Formed during the Molding Process

1993 ◽  
Vol 66 (9) ◽  
pp. 2515-2521 ◽  
Author(s):  
Masaharu Okazaki ◽  
Kazumi Toriyama
2007 ◽  
Vol 56 (9) ◽  
pp. 5502
Author(s):  
An Zhen-Lian ◽  
Yang Qiang ◽  
Zheng Fei-Hu ◽  
Zhang Ye-Wen

2020 ◽  
pp. 096739112095324
Author(s):  
Nikita Gupta ◽  
PL. Ramkumar

Rotational Molding is a plastic manufacturing process mainly implemented to produce stress free hollow products. Linear Low Density Polyethylene (LLDPE) is widely preferred as base resin for molding roto molded product, but it displays moderate value in some critical applications where strength is the major criteria. Additives can fill the gap in sustaining the necessary strength needed. In the present work, an attempt has been made to analyze the optimum percentage of coir reinforced with LLDPE for rotational molding technique to provide requisite processability for rotational molding process. Coir in its powder form is mixed at concentrations varying in the range of 3% to 20% with respect to LLDPE. In order to justify the prerequisite of processability for rotational molding, various experiments namely FTIR, MFI, rheology and thermal analysis were conducted. FTIR suggested the range of 5% to 15% wherein the significance of LLDPE and coir peaks can be observed. MFI test supported FTIR result which ended in considering 3% to 12% by weight ratio suitable in terms of flow ability. Rheological and thermal analysis subjecting to shear and heat parameter respectively, confirmed the range of 10 weight percentage of coir or below is suitable in terms of material processability. From the experimental results, it is concluded that 10% or less concentration of coir fiber in LLDPE as an optimum range of blend yielding better processability for rotational molding process.


2020 ◽  
Vol 54 (28) ◽  
pp. 4359-4368 ◽  
Author(s):  
Hesham Elkawash ◽  
Seha Tirkes ◽  
Firat Hacioglu ◽  
Umit Tayfun

In this study, two kinds of mineral fillers, bentonite (BNT) and barite (BRT), were incorporated into low density polyethylene (LDPE) by extrusion process. Silane treatment was applied to BRT and BNT surfaces in order to increase their compatibility with LDPE matrix. Surface characteristics of fillers were examined by Fourier transformed infrared spectroscopy (FTIR). LDPE-based composites were prepared at a constant concentration of 10%wt for each additives. Test samples were shaped by injection molding process. Mechanical, thermo-mechanical, water repellency, melt-flow and morphological characterizations of LDPE and its composites were performed by tensile and impact tests, dynamic mechanical analysis (DMA), water absorption test, melt flow index (MFI) measurements and scanning electron microscopy (SEM) technique, respectively. Test results showed that surface treatments led to increase for final properties of composites since they promoted to stronger adhesion between minerals and LDPE matrix compared to untreated ones. Tensile and impact strength values, storage modulus and glass transition temperature of LDPE were improved by inclusion of silane treated minerals. BRT and BNT additions caused no remarkable changes with regard to MFI of LDPE. Additionally, silane modified mineral filled composites exhibited remarkable water resistance behavior. According to SEM analysis of composites, silane treated BNT and BRT containing samples displayed homogeneous dispersions into LDPE phase whereas debondings were observed for untreated BNT and BRT filled composites due to their weak adhesion to polymer matrix.


2021 ◽  
Vol 1021 ◽  
pp. 290-298
Author(s):  
Abduati Elnaid ◽  
N.Z. Noriman

The effect of different content of steric acid (3, 6 and 9 wt.%) on the mechanical properies (tensile, flexural and impact properties) and morphology of linear low-density polyethylene / date seeds (LLDPE/DS) composites were evaulated in this research. The composites were produced by using extrusion followed by injuction molding process. Results presented that the addition of steric acid at 3 wt.% to the composite has shown highest tensile strength and elongation at break as compared to other treated samples. This is due to the improvement on the fiber surface in presence of SA. However, the tensile strength and elongation at break decreased thereafter treatment with 6% and 9% of SA. Furthermore, the flexural and impact properties have shown the same trend of the tensile properties, this was consistent with the results shown on SEM micrographs.


2009 ◽  
Vol 34 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Souad Djellalia ◽  
Nassima Benmahmoud ◽  
Tahar Sadoun

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